Screw-cutting die



(No Model.)

0 L BUTLER SCREW CUTTING DIE.

No. 477,293. Patented June 21, 1892.

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UNITED STATES ATENT Fries.

CALVIN L. BUTLER, OF GREENFIELD, MASSACHUSETTS.

SCREW-CUTTING DIE.

SPECIFICATION forming part of Letters Patent No. 477,293, dated June 21,1892.

Application filed March 8,1892. Serial No. 424,183. (No model.)

To all whom it may concern.-

Be it known that I, CALVIN L. BUTLER, a citizen of the United States,residing at Greenfield, in the county of Franklin and State ofMassachusetts, have invented certain new and useful Improvements inScrew-Cutting Dies; and I do hereby declare the following to be a full,clear, and exact description of the invention, such-as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to an improvementin screw-cutting dies.

It consists, essentially, of a die formed in two parts placed togetherin a suitable holder. Said two parts where they meet are splayed attheir outer lines of contact to form opposite V-shaped openings betweensaid parts and the rim of the holder to receive the conical ends ofscrews which may be driven through said holder radially to wedge thesaid parts of the die iinmovably to the rim of the holder and againstlateral or rotary movement. The die is provided with an annular groove,located centrally as to its depth, into which are fitted severalfeathers provided with outwardly-projecting studs, which pass throughopenings in the rim of the holder. The die-holder has an annular groovecorresponding with the groove of the die and immediately opposite itwhen said die is in place for work. The several feathers mentioned fitinto bo h grooves and they are adjusted to place from the outside of therim of the holder. Four screws are run into the rim of the die-holder,two of which have conically-pointed ends and the other two have flatends which bear against the outer surface of the die when they are Thedie-holder is of the usual form with the exception that it has thegroove previously mentioned cut from the inner surface of its rim.

In the drawings illustrating my invention, Figure 1 is an elevation orface of the die and holder. Fig. 2 is a section of the die and holdertaken in a plane which cuts through the annular grooves of the same.Fig. 3 is a section of the die and holder taken in a plane at rightangles to the plane of section of Fig. 2. Fig. 4 is a perspective viewof the two parts of the die.

Similar reference-letters of the drawings indicate like parts in all ofthe figures.

Referring to the drawings, A is the holder for the die, provided with acentral opening ct,

lateral openings b, groove 0, and four holes d in its rim to receive thestuds of the feathers to be mentioned, and screw-threaded openings e forthe four screws ffg g.

B are the feathers, provided with studs h.

The die is composed of parts i i, each splayed at points is. Z is theannular groove in the die, and c the corresponding groove 1n the rim ofthe 11 older. at is the screw-threaded opening, corresponding with theopening a of the holder, and lateral openings 9?. correspond with theopenings 1) of the holder.

Small openings 0 are formed in the die from its face to a depthsufficient to reach the feathers, so that by means of a pointedinstrument the release of the die from the hold of the feathers may beeffected when it is desirable to take thedie from its holder. V

In fixing the die for service the feathers are first placed in theannular groove of the holder with their studs extending through theholes in the rim provided to receive them. The two parts of 'the die 2'2' are now placed in the holder and the four screws ffg g driven inward.The conical ends of the screws f f take into the opposite V-shapedopenings of the dies and wedge the two parts of the die against thescrews 9 g. The feathers B are now adjusted to place in the groove ofthe die to hold it against axial movement. The feathers interposed ingrooves between the holder and the die and serving to hold the die toplace in the said holder against axial movement are impinged upon by theinner surface of the wall of the usual die-stock, and thus held rigidlyto proper engagement.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. The combination, with a screw-cutting die-holder provided with anannular groove formed outward from within, and holes radiating outwardthrough said groove, as described, and the die in parts with groovescorresponding with the groove of the holder, of feathers provided withstuds adapted to engage the grooves of the holder and die and extendthrough openings of said holder, as grooves of the die and holder andunscrewand for the purpose set forth. threaded holes of the latter, theconical screws,

2. The combination, with a holder for a and flat-pointed screws, allarranged substanscrew-cutting die having a cylindrical wall tially asand for the purpose set forth. 15 5 perforated radially with alternatingplain and In testimony whereof I affix my signature in screw-threadedholes and provided with an presence of two witnesses. annular groove outfrom within outward, of the screw-cutting die formed in parts havingsplayed angles, each part provided with a, [O groove corresponding withthe groove of the holder, feathers with studs fitting into the CALVIN L.BUTLER.

Witnesses:

J AMES S. GRINNELL, WM. H. ALLEN.

